Together forever: lovers on the Pont des Arts in Paris. The locks have now all been removed.
Photograph: Chesnot/Getty Images

A few years ago a man – let’s call him Edward – went on a romantic minibreak with his girlfriend. They went to Paris. Poetically, it was the city of love. Practically, there was a Eurostar deal on at the time.

Edward and his girlfriend were in the early days of their relationship. They had met through university friends and the spark had been immediate: locked eyes across a dinner table; a shared interest in the same Netflix box sets and a mutual liking for the music of Father John Misty.

When they got to Paris they spent hours walking through the streets arm in arm talking about the things that couples do when the future seems infinite and hopeful. They spoke of children’s names and significant others and whether they did or didn’t like Marmite (Edward did; his girlfriend didn’t). And then they stumbled upon the historic Pont des Arts.

In truth Edward had secretly planned for them to end up there. In his coat pocket he had a padlock purchased the week before from Robert Dyas on to which he had etched their initials on either side of a rudimentary love heart. He took the lock out and showed it to his girlfriend, explaining that he intended to fix it to the railings of the bridge. The lock would stand forever as a beautiful tribute to their lasting love.

The girlfriend was touched. They kissed. Edward clipped the lock on to the metal grate, where it jostled for space with several hundred other padlocks left by several hundred other loved-up couples and then he flung the key into the waters of the Seine. “It honestly felt like one of the most romantic things I’d ever done,” Edward says now. “It was so symbolic.”

The locks on the Pont des Arts were blamed for the collapse of the bridge’s parapets

Edward doesn’t want to give his real name because he’s a bit embarrassed. A few months after their trip to Paris, the couple broke up. It wasn’t anything particularly dramatic, he says, just a slow realisation that they weren’t meant to be together after all. The lock, however, remained firmly in place. Edward spent a lot of time thinking about that lock. It began to obsess him: the notion of it being permanently affixed to a bridge in Paris, its physical presence having outlasted the human relationship it was meant to represent.

“I kept imagining it there, almost like it was taunting me with how naive I’d been,” he explains. “It seemed so stupid, looking back.”

Then, last June, the Parisian authorities started to cut away the locks. There were now over a million of them and the weight had been blamed for the collapse of part of the bridge’s parapets. There was concern there might be further collapse. Forty-five tonnes of metal were removed – among them Edward’s heartfelt purchase from Robert Dyas.

As yet no one knows where the so-called “love locks” have been taken or what the city council intends to do with them. There are rumours of an auction or an art installation. Edward doesn’t particularly care. He is just relieved the lock has been removed – and with it an uncomfortable memory of love not working out in the way he’d hoped.

Lock and load: last June Paris authorities began removing the locks on the ancient Pont des Arts. Photograph: Chesnot/Getty Images

Over the past decade, love locks have sprung up in cities across the world, emblazoned with lovers’ initials, declarations of undying affection and sometimes even marriage proposals (one lock left on Brooklyn Bridge stated simply: “Carrina, will you marry me?” written in marker pen). In Canada they have appeared along the Wild Pacific Trail on Vancouver Island. In Australia they have been left on a fence overlooking Lake Hume in New South Wales. In Las Vegas they are left on the half-scale model of the Eiffel Tower at the Paris Hotel. In Taiwan they are hung in pairs on an overpass at the Fengyuan railway station in the belief that the magnetic fields generated by moving trains will imbue them with positive energy and make wishes come true. And at Gretna Green in Scotland, scene of runaway marriages through the ages, specially designed lightweight padlocks are available at £19.99. The gold- coloured lock can even be personalised with laser engraving.

“There’s no key,” the Gretna Green website states in its product description. “These unique love locks lock one time only, meaning that once your love is locked, it is sealed for ever.”

Sealed, at least, until rust corrosion takes its natural course or the structure in question starts to collapse under the weight of the metal. It is not just Paris that feels the need to protect its heritage from such romantic impulsiveness. Some 5,000 locks left on the Ponte Vecchio in Florence were removed by city authorities because they were deemed to be ugly as well as denting the metal structure of the bridge. The same thing happened with Dublin’s Ha’penny Bridge in 2012. In New York a group of “lock pick” enthusiasts organised an expedition to remove the locks on Brooklyn Bridge in 2013 and save them for a piece of public artwork before the authorities removed them – a week later, new locks had already sprung up in their place.

Love locks are divisive. Jonathan Jones, the Guardian art critic, has written that the practice is “as stupid as climbing a mountain and leaving a crisp packet at the top, or seeking out the most unspoilt beach and stubbing out cigarettes in the sand. Seriously. This is not a romantic thing to do. It is a wanton and arrogant act of destruction. It is littering. It is an attack on the very beauty that people supposedly travel to Paris or Rome to see.”

Who doesn’t engage in magical thinking to ward off the terrifying spectres of separation and loss?

So where does our need to lock our initials on to a chunk of historic metal come from? According to some, it stems from an ancient Chinese tradition. Others believe it started in the Serbian town of Vrnjacka Banja during the First World War, when a local schoolteacher was left heartbroken after her army officer beau was sent away to fight in Greece and fell in love with a woman in Corfu. The story slipped into folklore and couples began leaving padlocks on the bridge where the teacher and the army officer used to meet.

Then in 2006 Italian author Federico Moccia wrote a cult novel entitled I Need Youabout lovers fixing locks to a lamppost on a bridge in Rome – the idea was picked up by teenagers, then tourists and then, it seems, by the rest of the world. Moccia insisted in an interview with the Italian newspaper La Repubblica that he did not regret his part in the phenomenon: “The padlocks are a symbol of love and something to be proud of. Tourists go to Ponte Milvio to see them, and I’m proud of that. In any case, better a padlock than graffiti disfiguring the walls.”

And as Edward discovered, there is a natural human impulse to give permanent shape to a mutable human emotion, as if by lending it a physical presence we can mitigate against love’s fragility. Are we seeking to protect ourselves against loneliness by leaving our mark both on a city and on someone else’s heart?

The author Olivia Laing, whose forthcoming book The Lonely City is a cultural history of loneliness, says that although love locks are “exceptionally irritating, I understand the sentiment. Love is such a vulnerable state: who doesn’t engage in magical thinking to ward off the terrifying spectres of separation and loss?”

And in some ways leaving a padlock on a bridge is no different from carving one’s initials in a tree: in a transient world there is the same impetus towards ownership (“I woz here”) and preservation (“I will be remembered”).

“It’s the triumph of hope over experience,” explains Ivan Ward, deputy director of the Freud Museum in London. “People like to express their love or make declarations of love, and locking a padlock and throwing away the key seems to be a straightforward symbol of fidelity and commitment. Forsaking all others. We want to be the ‘only one’ with the sexual partner as we wanted to be with the mother, and how much more certain can we be if we actually – ie symbolically – lock someone in? I suppose it is potentially less embarrassing than getting the name of your beloved tattooed across your bottom.”

Key to my heart: while the locks are being removed from some tourist attractions, other authorities are raising funds by creating special padlocks for lovers. Photograph: Allan Swart/Alamy

True. And there is some base, primal appeal in the idea of being locked on to someone else in the midst of life’s uncertainty. In Padua, Italy, there is a historic custom of presenting St Valentine’s keys as romantic gestures each year in order to “unlock the giver’s heart”. The notion of leaving a lock on a bridge emphasises that element of danger: the risk of falling into a void unless one is anchored to something stable and lasting.

“Love can save us from that,” says Ward. “I presume that when couples do their love-lock ritual they feel really happy, but Freud, always the pessimist, usually finds some kind of anxiety lurking beneath the surface. And separation anxiety is one of the big ones.”

Now, as if to compound our separation anxiety, we’re even being separated from the idea of love locks themselves. Some cities, anxious about their environmental impact, have banned them altogether. After the Rialto Bridge was covered in padlocks fixed to the iron brackets and bars which helped keep the 16th-century structure together, the city of Venice removed them and introduced a €3,000 fine for anyone with the temerity to add a new one. A campaign called Unlock Your Love produced leaflets stating: “Your love doesn’t need chains. Venice doesn’t need your garbage.”

In Chicago the authorities have been systematically cutting off padlocks to stop them falling off and hurting people when the city’s moveable bridges are lifted for boat traffic, while in Berlin leaving a love lock is now punishable by a fine after rust damage was noted on two of its bridges.

Yet the craze looks set to continue. Edinburgh’s Forth Road Bridge raised more than £10,000 in 2014 for the local lifeboat service after dedicating four panels for passersby who wanted to buy and fix their padlocks to the bridge. Moscow has introduced metal trees where couples can leave their locks. And these days you can even purchase a “virtual” love lock to express your feelings of intimacy and affection online.

It all comes too late for Edward, however. This Valentine’s Day he’s not planning any grand romantic gestures. He’s bought his girlfriend a card. Once she’s read it, he thinks it will probably go in the recycling bin.